Watt, Homer A., author
Barnes & Noble, 1957
Buku Referensi
edited by Margaret Drabble
Oxford University Press, 1985
Buku Referensi
Wilson, John B., author
Longmans Green , 1958
Buku Teks
Bateson, FW
Longmans , 1965
Buku Teks
Watson, George, author
Macmillan, 1991
Buku Teks